Coil winding die



Oct. 3, 1933- s w s N 1,929,156

COIL WINDING DIE Original Filed Dec. 28, 1929 INVENTOR .5. 14/143,575

ATTORNE Patented Oct. 3, 1933 PATENT oFFicE- COIL WINDING DIE StenWadsten, Bloomfield, 'JL, assignor to Westinghouse Lamp Company, a

Pennsylvania corporation of Original application December 28, 1929Serial No. 417,187.- Divided and this application tober 15, 1931. SerialNo. 568,953

2 Claims; (Cl. 1536.5)

The present invention relates to an improvement in machines forhelically winding a filamentary'wireas shown and describedin Patent No.1,670,499, May 22, 1928, to 'John W. Eckstedt and relates moreparticularly to a coil-winding die for use in'such machines, and is adivision of my copending application Serial No. 417,187, filed December28, 1929. r

I In the above-mentioned patent a machine is shown for coiling a finehair-like wire to ahelical form in the absence of a mandrel, andparticularly for the production of lengths of coiled wire to serve asfilaments for incandescent electric lamps. The said machine comprisesmechanism for moving a wire'through a given path by tangentialengagement with a pair of oppositely disposed driving rollers whichpropel the wire endwise into arcavity die which is so constructed thatthe wire issues therefrom in the form of a continuous helix. Means areprovided for cutting the helix into sections of proper lengths toconstitute filaments for incandescent electric lamps.

The die is so arranged that the cavity is positioned to receive the wirefrom the driving rolls, the bottom of the cavity being inclined orgrooved so that the wire is bent into a succession of coils which passover a lip or separator member at the edge of the cavity. The successiveturns of the coil or helix which issues from-the die are consequentlyspaced a given distance apart and the helix is, therefore, provided of acertain diameter and pitch depending upon the dimensions of the spacermember and the radius of curvature 'of the effective surface of thecavity as well as the position of the die with respect to the drivingrolls.

In the manufacture of coiled filamentary-bodies which serve aselectrical resistance elements when used as lamp filaments, it isessential to-exercise extreme accuracy in the formation ofthe coils,since each'filament or coiled section must be made in accordance withspecified dimensions so that each coiled section will have a length ofwire therein equal to the succeeding coiled sec- 5 tion. Furthermore,the diameter of the coil as well as the spacing or pitch of the turns'ofthe coil must be uniform. i

The dimensions of the diameter and'the proportions of the coiledsections vary for lamps of different wattage, and the data relating tosuch dimensions and proportions is known as the rating so that a coiledsection ror "a given rating must be made in accordance-witha-predetermined set of dimensions. For example, a filament for a 60 watt115 volt lamp must conmentioned patent a coil-winding die is shown anddisadvantage since when applying a die into posiwill be in accordancewith the data supplied for "production of the die is reduced by the timeand ercise considerable care as above mentioned. in

tain a length of wire of 517 mm., it must'have a diameter of .0108 inchand the coiled section must-contain 398 turns per-inch. The diameter ofthe wire also varies in filaments of difierent wattage lamps, and thediameter of the wire of a coiled filament of a watt lamp is preferably.00187 inch.

- It will be obvious that in order to produce a lamp filament and holdthe coil formation to the required proportions and dimensions itisnecessaryto accurately form the coil-winding die and toprovideaccurately adjustable means for holding the said die in a given relationto the path of movementof the wire thereto- In the abovedescribed aspreferably consisting of an extreme- 1y hard material such vas adiamond.A diamond die, although having indefinite life, is difficult to produceand owing to variations in the properties of a diamond, it .is veryoften brittle to the extent that portions of the coil-winding lip arebroken off rendering the die inoperative for the purpose intended.

As set forth in the said patent the coil-winding die may be constructedfrom hardened steel, but inasmuch as the wire passing over the dieresults in excessive wear, it is necessary to replacethe steel die atshorter intervals than is necessary with a diamond die. Ordinarily thereplacement of one die for another would offer a considerable tion forthe winding of a coiled filament, it is necessary to adjust the die inseveral planes until the cavity is accurately located in such positionthat the diameterand pitch of'the" coil produced the rating of theparticularlamp for which the filament is to be used. 1

When using a diamond die, the die remains in the machinefor: such a longperiod that the amount of labor and inconvenienceinvolved in a changefrom one dieto another isnegligible. A

steel die, although easier to produce, must be changed at comparativelyshort intervals and the advantage given by the facility accompanying thelabor involved in replacing the same.

It will further be understood in order to wind fine filamentary wire; tohelical form in accordance with given dimensions, it is necessary toexaccurately locating the die cavity. When it is necessary, therefore tochange the die owing to wear, dimculty is encountered in replacing a newdie in exactly the same position as that previously occupied by theremoved die. no

In my copending application Serial No. 242,715, filed December 27, 1927,for adjustable holder for coil-winding dies, apparatus is shown whereina die may be made of steel while positioned in a holderand so arrangedthat the die when finished may be inserted into the coil-winding machinein exactly the same position as occupied by a die which was produced bymoving a matrix against a soft-metal die blank and compressing thematerial of the blank to form a die cavity. Although this method issatisfactory it requires a time interval and necessitates considerablecare as well as the use of a certain amount of apparatus.

An object of the invention is to provide a coil winding die of vitreousmaterial.

Another object of the invention is to provide a coil-winding die havinga hard smooth glassy surface.

Other objects and advantages of the invention will be more fullyunderstood as the description proceeds.

In accordance with the present invention a coilwinding die is producedby moving a matrix into contacting relation with a die blank consistingof a vitreous material such as glass, while the said blank is in aplastic condition. In practicing the invention a coil-winding die ismade, for example, for the formation of filaments for 40 watt lamps.

This die may be made of steel or other hard macavity,

terial and adjusted in aholder in the machine until it is inthe exactposition to, wind coils for .the rating required. 7

While in its adjusted position in the holder it is moved into contactwith the end of a matrix blank and. forced thereagainstuntilan-impression of the end of the die is formed in the matrix blank.thus producing a matrix member.

This matrix member is then held in a given position and a die rod havinga tip consisting of a -vitreous material is positioned for movement intocontact with the matrix. The vitreous material may be heated by a finepointed flame until its exposed portion is in a plastic state at whichtime -.Iit.may be moved into contact with the matrix so that thevitreous or die portion of the die blank formed to constitute a cavitydie and ready tobe positioned in a coil-winding, machine. 1 By. reasonof the present method a die may :be-produced in a rapid and efiicientmanner so that if during the winding of a quantity of coiled "filamentsit becomes necessary to renew the die, .such operation may beaccomplished with a minimum loss of time.v

The invention will be more fully understood by reference to theaccompanying drawing in which:

Fig.1 shows a portion of a coil-winding machine partly in section withthe coil-winding die in position, 1 Fig. 21s a side elevational viewshowing apparavtus for moving a die blank in contact with a matrix .fora die-forming operation,

Fig. 3 is an enlarged view of a master die and a matrix member incontact to form the wirea bending cavity in a matrix,

Fig. 4 is a view showing the master die and matrix after the latter hasreceived its wire-bending Fig. .5-is a side elevational view of aportion of a matrix member partly in section,

-showing the die-forming cavity,

Fig.6 is a top'end view of a matrix member Fig. 7 is 'a side elevationalview partly. in sec- 'tion showing a die blank'with a diecavity formedjin'a vitreous portion at itsvend,

Fig. 9 is an enlarged fragmentary cross-sectional view showing theformation of a coil-winding die with a portion of a coiled wire.

Although the present invention may be practiced to produce a cavity die,for use in coilwinding machines where adjustment is necessary, it ispreferable to practice the invention for producing a die in apredetermined position with respect to a machine element for applicationto a coil-winding machine.

Fig. 1 shows a portion of a coil-winding machine-comprising a holder 10hinged at 11 to a spindle 12 which spindle is journaled in a suitablebearing on the body of a coil-winding machine. By reason of the pivot 11and the spindle 12 it is possible to move the casing 10 in a verticaland-a horizontal plane and adjust a die 13 with relation to wire drivingrollers or rolls 14 and 15 which propel a wire 16 against the die 13..The die may comprise-a die rod 17 and since it is essential to providea more accurate adjustment of the die than may be accomplished by theabove-mentioned vertical and horizontal adjustment, a sleeve 18 isprovided to receive the die rod 17 which sleeve is fitted in a suitablebore 19 in the casing 10. v

The sleeve 18 in which the die or die rod is positioned many be termed adie sleeve or collar and a set-screw 21 is provided to engage a notchordepression 22 in the die rod to hold it in a predetermined relation tothe sleeve. An adjustment of the die rod about its longitudinal axis maybe obtained by a rotary movement of the sleeve 18. For this purpose thesleeve is provided with a yoke 23 having a split head 24 by means ofwhich a clamping screw25 secures the yoke to the said sleeve 18. Arms 26and 27 extend downwardly from the yoke and are positioned on oppositesides of a control arm 28 integral with the casing 10, set-screws 29 and30 passing through threaded apertures in the arms serve to permit anadjustment of the yoke with a consequent adjustment of the sleeve 18 andthe die rod 17. I

A further adjustment of the die rod is accomplished by providing aset-screw 31 which extends through a threaded aperture in the yoke 23and abuts against the casing 10 thus by manipulationof the set-screw 31the sleeve and consequently the die may be moved toward or away from thewire driving rollers 14 and 15.

For the purpose of clamping the sleeve in its final position the casing10 is split and clamping screws 32 are provided.

The above tool or die holder constitutes part of a coil-winding machine,and it is thought that the above description is sufiicient for thepresent purpose in showing the die holder and the means for holding adie in a given relative position in the holder.

It will be appreciated that by reason of the above-mentioned adjustingelements the position of the holder may be changed with an extremelyfine degree of accuracy and that the die may be adjusted with relationto the holder.

In producing a die for application to the holder such as that shown inFig. 1 a die rod 17 may be provided with a tip 33'consisting of avitreous material such as glass, good results having been obtained fromglass .such as pyrex, it being understood, however, that various glasscompositions may be employed.

6 a matrix 35 is provided having a die forming lilo r .1 ,929',1"5'e Vrecess 3'1, thbottom surfaee of which pm 'vided'witharaised portion orfin 38. The matrix is employed-to receive the tip 33" when the same hasbeenrendered-jplastic so that the saidtip will take the'rverse formofthe recess 37 and a die-forming cavity 39 will be produced with acoil-winding lip 41 in thepro'per relative 'posi non. The operation ofbringing the matrixand the vitreous tip of the die blank into contactwill be more clearly understood by 'reiferencetoFig.v -'2 "which -showsanapparatus comprising a holder 42-to receiyea sleeve l8 whichis'substantially a duplicate "of-the "sleeve 18 and in-which may bedisposed a die rod 17 having a vitreous die blankatmne'end thereof. Aset-screw 21 .en-

gages a seat 22' to hold the die rod in a; given position with respectto thesleevelil' and the said sleeve is positioned in'the holder 42 andsecured by a' set screw 43. Adjacent to the holder 42 is positioned ahorizontal bearing bracket'44 having a bearing 45 in which a slidableholder 46 is positioned. V i o The holderv 46 is provided with a bore4'7 in which the matrix35 is positioned. A set-screw 48 is provided tosecurethe matrix in position and the bearing bracket 44 is provided witha slot 49 to permit the set-screw 48 to travel with the slidable holder46. V v

The matrix 35 is arranged withits longitudinal axis coincident with thelongitudinal axis'of the die rod so .thata movement of theslidableholder will move the recess 37 of the matrix into contactingrelation with the vitreous tip'of the die rod.

For the purpose of forming the, vitreous tip to the shape of the matrix,a burner nozzle 51 is provided'to direct a fine needle-point flame 52against the surface of the vitreous tip 33 to render it sutlicientlyplastic to take an impression.

The slidable holder 46 is actuated 1w move the.

matrix 35 by means of ahand-lever 53 having a slot 54 to receive-a'pivotpin 55 provided in a.

projection 56 integral with the slidable holder. The lever 53 is pivotedat 5'7 and is provided with a link 58 pivotally attached at 59 to one.end'

of a valve arm 61 of a valve 62 controllingpthe While the arm 53.is inits retracted or initial position the link 58 operates to direct theneedle flame 52 against the vitreous die blank. As the arm 53 is movedto advance the matrix the valve 62 is closed to remove the flame and asthe matrix advances, to the position shown in dotted lines the softenedend'of the die.

blank is impressed with the die formation.

It will be understood that the flame 52 may not be entirely'extinguishedbut lowered'to a mere pilot light so that when the, lever arm 53 returns"the matrix, the flame may then issue from the nozzle 51 ready to heatanother positioned die blank.

The bearing bracket 44 is provided with an.

adjustable stop 63 so arranged as to terminate the advance movement ofthe slidable holder and thus form the effective die face in a 'predetenmined position as indicated by the arrows X with respectto the set-screw21'. Thus when a die has been used and has worn or does not give theproper winding, the die rod 17 may be inserted in the sleeve 18 and theend softened and a new die formedimmediately.

It will be understood that although anew die rod mayibe employed havinga new tip, it

is, in many cases, only necessary to reheat the end of the vitreous tiphaving the die formation to renew the die form. Inasmuch as the die ismade in exactly the position that it'is used 'removedg 'as-shownin Fig-4thelrecess' 37 and the new die'may bereadily set up in the machine,without further "adjustment since it occupies the exact position of-the die-previously employed.

It desirable to make the matrix 35 froma die which is actually used towind coils to a given rating data as. for example a die; may beimade Vof steel or other hard material arid'placed in a machine to wind coilsand adjusted and ground,

: amuntil itxis exactly right for the windingof-coiledfilaments for agiven wattage. Th s die which in-Figs'. 3 and $4 ,is designated by thenumeral 64 is then forced into contact with one end of the matrix rod35- until an impressionis made as'shown in Fig. 3. When the die 64 isthe fin'38 has been formedand the matrix35is ready to be positioned in aslidable holder 46 for movement into contact withthe softenedend of thedie blank.

When forming the die by a movement of the matrix toward the die blank itmay be preferableto heat the matrix and for this purpose a burner 65 isprovided.

It will be understood that the said burner may be operated toclose' offas the slidable holder advances or it may be a continuous flame of rel-.

1 atively low temperature to maintain the matrix heated so as not tochill the die under formation.

It will also be understood that if desirable the flame 52 may, after,the die blank has been formed, operate to'supply only sufficientheat toanneal the formed die.

As hereinbefore set forth, coil-winding diesmu st. obviously be producedof different dimensions for'the manufacture of filaments for lamps no adefinite color has beenassigned to a lamp of a given wattage. theselection of the proper die is facilitated and a considerable amount oftime is saved. i

By reason of the present invention a mandrelless'coil-winding machinemay be operated continuously, and in the event that a new die isrequired the same may be produced without an appreciable amount ofdelay.

. Fig. 9 shows a perspective view on anenlarged scale of a coil-windingdie such as employed in connection withthe present invention and itwillI be noted that this die includes a lip 41 and a cavity 39. The .wire 16is driven into the cavity and issues in theform of a series ofconvolutions in l the form of 1a helix, the :turns of which areseparated by the lip 41 which determines the pitch. ,It will beappreciated that inasmuch as the entire action with respect to the wireand the die is a sliding or frictional engagement, it is desirable inorder to avoid wear to provide a die with an extremely smooth effectivesurface.

When employingavitreous materialsuch as glass 40 or enamel composition,it is possible to provide an effective winding surface having anunbroken layer or skin and when using fusible material the skinorsurface layer is extremely hard and wear resistant. Heretofore in themanufacture of a diamond die for example, a reasonably smooth surfacewas attainable but owing to the grinding operation the. cross-grainingof the material becameexposed and ofiered acertain amount of frictionalopposition to the passage of the wire ,thereover and caused wear. 1

5, in thee csse. of; a which. is ground,

tiles-same: result would occungiVV-hen formin a metailicdieby pressureitis not possible to get the -glazed smooth layer since the surface of themetal :is comparativelyirrough and remains.- so

whether the, die is formed by pressure orfby' grinding. I When forming a'die; :for the present purpose of avitreous material a new. article a isproduced in that itjprovides a boil-bending; elemerit havingthedesirable continuous glazed or v slippery surface giving the desirablewear-reproperty whioh,;-.in conjunction with the fact-Tttmt the saiddies may be madeat a more rapidrrate thandies heretofore produced; makesthe present invention -,a decided advance step mthe art ofcoilwinding'i- I i 1. Adie for helically winding comprising a rod havingone 'end tipped with vitreous material having a coiling-winding cavity..

Although a preferred embodiment of the invention is shown and describedherefm it is to be understood that; modificationsmay be made thereinwithout -,depa,rting (from the spirit and scope of the invention as set-f orth .in the appended claims. 7 I

What-is claimed is: 7 I Y lamp filaments

